Using proxies for clips produces black rendered video


First a disclaimer: I'm using a bit ancient version of Kdenlive:
- kdenlive-
- mlt-0.7.6

These are packages from RPMFusion (I'm using Fedora).

Now, the problem I'm facing is that when I enable proxies for any clips in my project, those clips get rendered as black screen to the rendered video. The clips that don't have the proxy enabled render just fine. I don't have the "Render using proxy clips" selected in the render dialog.

My project is really simple. The clips are Ogg Theora videos. They have the same dimensions and framerate as the project output. There is only one video track on the project where (parts of) the clips are organized. No effects, transitions or anything else either - just the plain clips on the track. There is no audio in the clips nor in the project.

The same problem occurs if I "render" to script and then execute that script. I produced two versions of scripts from the project. One is having the proxy for a clip enabled, one is not. Everything else in the scripts are identical.

Without proxy:
With proxy:

These scripts seem to have some differences if you compare them.

I can off course circumvent this problem by disabling the proxies before I render but that seems a bit cumbersome.

Any help on the subject?